I. Field of the Invention
The present invention relates to dispensers of the type which provide beverages by delivering a measured quantity of syrup together with one or more other fluids such as water into a container for consumption, and more particularly to improved systems, methods and apparatus for delivering consistent quantities of syrup in dispensing and vending machines using bag-in-box (BIB) syrup packages.
2. Description of the Prior Art
Bag-in-box (BIB) syrup packages are used in a wide variety of different beverage dispensers and vending machines. A typical dispenser delivers a quantity of syrup from the BIB together with a quantity of water and/or other fluid to form a beverage, such as soda. When activated, a typical dispenser will simultaneously deliver both syrup and water to form the beverage. The syrup and water may be delivered for as long as the dispenser is activated, such as a hand-held dispenser used at a wet bar; or for a measured time interval after the dispenser is activated, such as a pre-programmed dispenser at a fast food restaurant. Other commercial applications include vending machines that dispense a pre-determined quantity of syrup and other fluids (typically water) into a single-serving cup or reclosable pouch. Such vending machines may include a plurality of BIB syrup packages, allowing the user to select from a plurality of flavors (syrups) each of which will be delivered in a measured quantity along with a measured quantity of filtered water and/or other fluids into the cup or reclosable pouch. In many existing BIB delivery systems, water volume is measured using a flow meter that is located upstream of a mix manifold, and syrup (concentrate) volume is controlled by peristaltic metering pumps—one for each of flavor selection of the manifold. It is important for such systems to be able to detect when the BIB package is empty. Otherwise, the machine may deliver an inadequate quantity of syrup if the BIB package is running low, or the machine may deliver no syrup at all if the BIB package is empty. In the first scenario, the result may be in a watered-down beverage; and in the second scenario the result may be a water-only (no concentrate/syrup) beverage. Neither of these scenarios is acceptable to a consumer using such a vending machine.
In order to address this problem, some machines have used a count down program in the vending machine's electronic controller to calculate syrup volume/availability based on the number of vends from a given BIB package, multiplied by a predetermined volume of syrup per vend (depending on desired concentration). However, because of variability in the delivery systems used, which in some cases may be based on a vacuum generated by the flow of water through a mixing device, these systems are not always able to determine exactly when the BIB becomes empty. As a result, such systems may potentially deliver drinks to the consumer having lower than desired concentrate levels, or no concentrate at all. To address these undesired possibilities, a safety margin level has been used to shut down a particular syrup BIB when the theoretical syrup level in that BIB reached a point of approximately 20%. This approach reduces the potential of a consumer receiving a poor quality product, but at the cost of discarding as much as 20% of the syrup concentrate.
Other problems affecting reliable vending of syrup include failure to recognize a kink in the syrup feed line which could prevent proper syrup flow; and failure to recognize whether an empty BIB has been replaced with a full BIB at time of servicing, especially if the status of an empty BIB has been reset to “full.” These scenarios could also result in the machine dispensing lower than desired concentrate levels, or no concentrate at all.
To address these situations and attempt to reduce waste of syrup, peristaltic pumps with encoder circuits have been used to meter out the syrup. Use of the encoder data provides the ability to better track the volume of syrup dispensed during each vend, and allows the safety margin to be reduced from 20% to approximately 5%. Unfortunately this system is not without its own share of potential problems. For example, if the operator fails to route the syrup line tubing through the peristaltic pump correctly, the pump will cycle but no syrup will flow and the customer may receive a lower than desired syrup level, or no syrup at all. Also, this system cannot detect kinking of the syrup line that can restrict flow and result in the same problems. Moreover, the addition of encoder circuits to each of multiple peristaltic pump motors adds a significant cost.
In another attempt to address these situations, attempts were made to detect a difference in the electrical current being drawn by the DC motors that drive the pumps when the syrup line is properly routed and filled with syrup as compared to an empty syrup line or a pump without a syrup line altogether. Unfortunately, this approach was unsuccessful because typical current variations from motor to motor were greater than the variations in current associated with the variable scenarios described above (full line, empty line, missing line).
Thus, the need remains for reliable delivery systems to precisely track the status of BIB packages, avoiding unnecessary waste of the contents of the BIB packages, and also detecting failure to deliver correct amounts of syrup from such packages.